Hot to define the directory for the dynamic libraries?

[wysota]

I'm afraid qt.conf won't help you with that. Qt libraries are linked by the dynamic loader, so QLibraryInfo doesn't have time to initialise itself before it is even loaded into process address space. You can only manipulate plugins search paths this way, but not Qt libs themselves.

Without qt.conf, the Qt libraries will use the hard-coded paths to look for plugins, translations, and so on. These paths may not exist on the target system, or they may not be accesssible. Because of this, you need qt.conf to make the Qt libraries look elsewhere.